Pictured above is an artist's conception of Sikorsky's new project. The Firefly, if successful, will be a full-sized helicopter that is powered entirely by electricity:

The Firefly is built around the existing S-300C helicopter, a popular two-seat trainer design that was originally built by Hughes Aircraft in the 1950s. The existing 190-horsepower, four-cylinder gasoline engine has been replaced with a 200-horsepower electric motor. Powered by lithium ion batteries, the Firefly will feature new cockpit displays, as well.